Ginseng saponin has a unique chemical structure different from that of saponin found in other plants. Thus, its pharmacological efficacy is unique, and thus it is also called “ginsenoside” in the sense of ginseng glycoside. Specific types of ginseng saponins include panaxadiol-type ginsenosides Rb1, Rb2, Rc, Rd, compound K, compound Mc, compound O, etc., and panaxatriol-type ginsenosides Re, Rf, Rg1, Rg3, Rg5, Rh1, Rh2, etc., and each of these ginseng saponins exhibit different efficacies.

As shown in the Reaction Scheme 1, particularly, since ginsenosides Rb1, Rb2, Rc, etc., which are panaxadiol type saponins, can be converted into other ginseng saponins by metabolism of microorganisms, a method using enzymes has been used for a long time as a method of converting ginseng saponin into other kinds of specific ginseng saponins.
However, for the conversion reaction using enzymes in the past, non-specificity of enzymes for a substrate is large and thus an extremely large amount of enzyme should be used relative to the saponin substrate used. Further, the enzymatic reaction is not completed with a desired ginseng saponin, but an additional reaction occurs nonspecifically. Thus, since other ginseng saponins were variously produced without being converted only to the desired ginseng saponin, the yield of the desired ginseng saponin was extremely low.
Conventional methods of obtaining ginseng saponins do not convert only to a desired specific ginseng saponin, but provide a technical solution of obtaining various converted ginseng saponins by extraction or the like and then purifying the resultant to isolate only desired ginseng saponins.
However, since these conventional methods require additional cost and time associated with the purification in order to obtain a pure specific ginseng saponin. Therefore, the selling price of ginseng saponins is inevitably increased, and there is a limit to applying a large amount of ginseng saponins to related products.
In particular, in the case of compound K, it corresponds to the compound which is finally produced in the pathway of the compound converted from ginseng saponin, and thus a variety of enzymes capable of reacting all intermediate metabolites are required, and further, the reactivity between the metabolite and the enzyme decreases due to metabolic products generated during the reaction. In addition, a problem arises that the yield decreases due to aggregation phenomena in the reaction solution between intermediate metabolites.